were chosen for this study because they contain hydroxyl groups, so that the wettability of the modified rubbers can be assessed. The change in their hydrophilicity may be used to indicate their potential compatibility with other polarmaterialshavingpolarhydroxylgroupssuchassilica, natural fibers or other polymers. The images in Fig. 9 clearly show that the contact angles of the modified NRs are smaller than that of NR film due to the increased polar
ity and hydrophilicity of the functionalized rubber, leading tohighwettabilityofthefilms.Thecontactanglesdecrease with increasing epoxide contents of the epoxidized graft copolymers. The lowest contact angles of 54 for water and 30 for DEG can be observed on the epoxidized graft copolymer with 30 mol% epoxide film, indicating the highest level of polarity, due to the combined effect of the epoxide groups and the grafted PMMA. Furthermore, the
Fig. 9.